package com.dayatang.product.webapp.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

/**
 * 文件名:VerifyImageUtil.java
 * 描述:生成验证码工具类
 * 创建时间:2012-6-11 下午5:06:56
 * 创建者:mluo
 * 版本号:v2.0
 */
public class VerifyImageUtil extends ActionSupport {

	private static final long serialVersionUID = -7088988462986701901L;

	public static BufferedImage getRandImage(String sessionKey) {
		
		// 在内存中创建图象
		int width = 57, height = 20;
		BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);

		// 获取图形上下文
		Graphics g = image.getGraphics();

		// 生成随机类
		Random random = new Random();

		// 设定背景色
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);

		// 设定字体
		g.setFont(new Font("Times New Roman", Font.PLAIN, 18));

		// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
		g.setColor(getRandColor(160, 200));
		for (int i = 0; i < 155; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}

		// 取随机产生的认证码(6位数字)
		String sRand = "";
		for (int i = 0; i < 4; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand += rand;
			g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(rand, 13 * i + 6, 16);
		}

		// 将认证码存入SESSION
		ActionContext.getContext().getSession().put(sessionKey, sRand);

		// 图象生效
		g.dispose();
		
		return image;
	}
	
	/*
	 * 给定范围获得随机颜色
	 */
	private static Color getRandColor(int fc, int bc) {
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

}


